2023 Chinese balloon incident

2023 Chinese balloon incident

The balloon photographed over Billings, Montana, on February 1
Date	January 28 – February 4, 2023 (2023-01-28 – 2023-02-04)
Location	Airspace over the United States, Canada, and territorial waters
Type	Airspace violation; diplomatic incident
Cause	High-altitude Chinese balloons entering foreign airspace
Motive	United States and Canada allege reconnaissance; China claims meteorology and force majeure due to westerlies
Participants	U.S. and Canada: USA Joe Biden Lloyd Austin Mark Milley Glen VanHerck (NORAD) Canada Justin Trudeau Anita Anand Wayne Eyre Other: China Xi Jinping Qin Gang Wang Yi
Outcome	Balloon downed by an AIM-9 Sidewinder fired by a U.S. Air Force F-22 Raptor; debris recovered

From January 28 to February 4, 2023, a Chinese-operated high-altitude balloon was seen in North American airspace, including Alaska, western Canada, and the contiguous United States. On February 4, the U.S. Air Force shot down the balloon over U.S. territorial waters off the coast of South Carolina, on the order of U.S. President Joe Biden. Debris from the wreckage was recovered and sent to an FBI Laboratory in Quantico, Virginia, for analysis.

The American and Canadian militaries announced that the balloon was for surveillance, while the Chinese government maintained it was a civilian meteorological research airship that had blown off course. Specifically, the U.S. said that the balloon was capable of geolocating electronic communications and carried intelligence surveillance equipment inconsistent with that of a weather balloon. It later added that similar Chinese spy balloons have flown over more than 40 nations. Analysts said that the flight path and structural characteristics of the balloon were dissimilar from those typically used for meteorological research.

The incident increased U.S.–China tensions and prompted U.S. Secretary of State Antony Blinken to delay a diplomatic visit to Beijing, which was set to be his first since 2018. The incident also increased Canada–China tensions as Canada summoned the Chinese ambassador over the violation of Canadian airspace. On February 3, the U.S. Department of Defense announced that a second Chinese balloon was passing over Latin America, and that China confirmed ownership of this balloon. The news was followed by subsequent detections and shootdowns of high-altitude objects over Northern Alaska (February 10), Yukon (February 11), and Lake Huron (February 11–12).

Background

Spy balloon history and technology

Further information: History of military ballooning

The use of balloons as military technology dates to the late 18th century and peaked during World War I. The United States and the Soviet Union continued to use them for reconnaissance during the Cold War. Despite being mostly obsoleted by surveillance satellites and drones, balloons have retained some advantages, such as a lower cost of production and deployment.

In 2019, the U.S. Department of Defense increased investment in high-altitude balloons with COLD STAR (Covert Long Dwell Stratospheric Architecture), a spy balloon that can lurk undetected in enemy airspace. The balloons have autonomous navigation, high fidelity sensors, and on-board AI that can be incorporated into the military kill chain as a complement to satellite-based systems.

In 2022, the U.S. Army Pacific Command sought to "operationalize the stratosphere" with persistent surveillance using balloons "the size of a college football stadium." Made of a polyethylene plastic and having minimal heat signature, the balloons are hard to detect while they loiter for days capturing 5-cm resolution imagery.

Soon after, Chinese officials and scientists highlighted the usefulness of balloons for their own civilian and military capacities. In 2022, the Chinese Academy of Sciences publicly disclosed pictures of their stratospheric balloon carrying a 1.2 ton payload, but said it was meant to carry scientific instruments. Other Chinese military publications suggested that balloons could be used to induce an enemy's air defense systems as well as a means of enhancing domestic air defense. The 2023 balloon is believed to be manufactured by a civilian Chinese defense contractor.

U.S.–China tensions

Further information: China–United States relations

The 2023 balloon incident occurred while U.S.–China relations were at their lowest point in decades, following suspected incidents of Chinese espionage and amid increasing strategic competition in military and economic sectors. In 2022, the U.S. and its allies imposed stringent export controls on "foundational technologies" (including advanced semiconductor chips) to China with the official aim of inhibiting any Chinese military buildup. The Biden administration has also sought to maintain critical supply chains independent from China.

Previous unidentified objects and suspected Chinese balloons

On February 9, 2023, the U.S. Department of State said that the balloon was part of a fleet of Chinese military surveillance balloons that had flown over more than forty countries, and across five continents, including Latin America and Europe.

This was the fifth detected Chinese balloon over the continental United States since 2017. Prior incursions suspected of surveillance activity had entered U.S. airspace over Florida, Guam, and Hawaii. One occurred earlier during Biden's presidency (2021–present) and three occurred during Donald Trump's presidency (2017–2021). They did not persist as long as the 2023 incident, and China was able to recover those balloons.

Other pre-2023 incursions have remained unexplained, classified by U.S. authorities as unidentified anomalous phenomena. Many were handed to the Defense Department task force responsible for investigating such events. The commander of United States Northern Command (USNORTHCOM), General Glen VanHerck, said that the U.S. failure to detect and identify all such incursions was "a domain awareness gap that we have to figure out".

In 2020 and 2021, similar balloons were sighted in Sendai and Hachinohe, Japan respectively, but they were not identified as of Chinese origin at the time.

In February 2022, several balloons were spotted off the coast of Taiwan, which their Ministry of National Defense said likely were for meteorological observations for the PLA's Eastern Theater Command and posed no immediate security threat.

Incident

Balloon

Comparison with the estimated size of the balloon

Size, propulsion, and payload

The balloon carried an underslung payload described as a "technology bay" estimated to be the size of "two or three school buses" and was powered by sixteen solar arrays mounted on the payload. The balloon was 200 feet (61 m) tall according to U.S. General Glen D. VanHerck. USNORTHCOM and NORAD Commander, General Glen VanHerck, estimated the payload weighed over 2,000 pounds (910 kg).

National Security Council spokesman Admiral John Kirby said the craft had a propeller and could be maneuvered. U.S. officials told foreign diplomats in Beijing that the craft had rudders and propellers. A Chinese Foreign Ministry spokesperson said it had "limited self-steering capability".

The U.S. Department of Defense said the balloon did not present a military or physical threat to people on the ground while it remained in the air, and that shooting it down over water would be safer and increased the opportunity to study the wreckage for intelligence purposes.

Signals intelligence capabilities

Images from U-2 flybys and forensic analysis of the payload showed antennas that likely were used for collecting and transmitting signals intelligence. A publicly released U.S. State Department document, after the balloon was downed and debris collected, said that the balloon's solar arrays produced sufficient power to run "multiple active intelligence collection sensors" and that the antennas on the balloon could collect and geolocate communications, including radio and mobile phone signals, but it was unclear if any specific devices were targets. U.S. authorities identified the manufacturer of the balloon with high confidence as a company with direct ties to the People's Liberation Army. U.S. officials cited this as an example of military-civil fusion, in which Chinese civilian enterprises are highly integrated into China's military structure.

Experts noted differences between the Chinese balloon and conventional weather balloons. Standard weather balloons have typically been around 20 feet (6 m) wide, less than a quarter of the Chinese balloon's diameter. Although weather sensors have become more sophisticated over time, their instrumental suites have remained relatively unchanged since the 1970s and 1980s, and have been consistent globally. Experts interviewed by the BBC said it was unusual for weather balloons to last as long as the one involved in the incident and that the balloon "might have been more sophisticated than China claims".

Former U.S. Air Force General and NORAD official Charles "Tuna" Moore said that the Chinese surveillance technology on the balloon was inconsistent with meteorological missions. He said that the Chinese would likely be interested in collecting emissions or signals from various radar, weapons, and communications systems to try to detect vulnerabilities in the defenses of the U.S. and its allies.

Detection

External videos
U.S. Air Force Brigadier General Patrick Ryder during the press briefing
Defense Department Briefing, February 3, 2023, C-SPAN

High-altitude (stratospheric) balloons are extremely difficult to detect. A 2005 study by the U.S. Air Force (USAF)'s Air University states surveillance balloons often present very small radar cross-sections, "on the order of hundredths of a square meter, about the same as a small bird", and essentially no infrared signature, which complicates the use of anti-aircraft weapons. A 2009 research paper by a USAF officer found that such aircraft "are inherently stealthy" because of a tiny infrared signature at high altitude (attributable to the balloon's inert gas which produces very low heat emissions) and because of the difficulty of radar detection (as the balloons lack sharp edges and metal structures).

The balloon's first reported sighting was on February 1, 2023, when civilians on a commercial airliner spotted it. On the same day, former Billings Gazette editor Chase Doak spotted the object above Billings, Montana, after seeing reports that the airspace around Billings was closed. He had initially assumed it was a star or a UFO. Doak contacted his friend and Billings Gazette photographer Larry Mayer, and the two photographed the balloon using telephoto lenses. Mayer also sent the images to various government agencies. After the photographs were published in the Billings Gazette and received widespread media coverage, the U.S. Department of Defense and the Canadian Department of National Defence announced on February 2 that NORAD was aware of a high-altitude surveillance balloon believed to belong to China and had been tracking it for "several" days. The balloon was flying at an altitude of 60,000 feet (18,000 m) over Billings at the time.

American defense officials considered shooting the balloon down but initially decided not to due to the risk of debris injuring civilians on the ground. A meeting was convened between Secretary of Defense Austin, Chairman of the Joint Chiefs of Staff General Mark Milley, NORTHCOM/NORAD Commander General VanHerck, and other military commanders. Biden was advised by officials not to shoot it down because debris could threaten civilians or cause property damage.

Flight path

Approximate route of the balloon

The balloon entered U.S. airspace above the Aleutian Islands on January 28, 2023, then moved across Alaska, and entered Canadian airspace over the Yukon and Northwest Territories on January 30, 2023. After flying southeast over British Columbia, the balloon then crossed into the U.S. in northern Idaho on January 31, and Montana on February 1, where it was spotted over Billings. Montana is the location of multiple nuclear missile installations, including Malmstrom Air Force Base, one of three U.S. Air Force bases from which intercontinental ballistic missiles are operated, raising suspicions that the balloon had been launched to surveil said nuclear installations. A meteorological researcher calculated a possible trajectory along this path using the HYSPLIT atmospheric model, consistent with data on prevailing westerlies from China to Montana. The balloon was spotted above northwest Missouri, near Kansas City, on February 3.

An unnamed U.S. defense official told The Washington Post that the balloon was not a derelict object as it generally followed jet stream patterns but loitered when it was near sensitive sites, such as the Malmstrom AFB. The Post said that that observation undermined Chinese assertions that the balloon was a wayward device. The U.S. ground-based intercontinental nuclear arsenal is composed of about 400 LGM-30 Minuteman III missiles deployed in missile silos around Malmstrom AFB, Montana; Minot AFB, North Dakota; and Francis E. Warren AFB, Wyoming. Experts interviewed by Time said that the balloon traveled at a much longer distance than what would be expected of a standard weather balloon and that Chinese officials should not have been surprised that the balloon would have eventually either crossed the U.S. or faced detection.

The balloon was flying at an altitude of 60,000 feet (18,000 m). In comparison, the Concorde was the only commercial airliner to fly at 60,000 feet (18,000 m). Business jets can reach 51,000 feet (16,000 m), current commercial airliners can reach 45,000 feet (14,000 m), and the SR-71 had reached 90,000 feet (27,000 m).

U.S. monitoring and counterintelligence

During the incident, a U.S. defense official stated that the balloon had "limited additive value from an intelligence collection perspective". Nonetheless, the Pentagon took steps to protect its assets from leaking sensitive information to the balloon. U.S. Secretary of Defense Lloyd Austin said the U.S. military was able to collect valuable intelligence on the balloon while it was transiting North America. VanHerck said that the U.S. Department of Defense obtained special authorization to collect intelligence against the balloon within the U.S.

The balloon was monitored by crewed aircraft deployed by NORAD, including a Boeing E-3 Sentry Airborne Early Warning and Control System (AWACS), a Boeing RC-135 reconnaissance aircraft from Nellis Air Force Base, and a F-22 Raptor from Langley Air Force Base. The U.S. Department of Defense said that, during the balloon's overflight of the United States, it had blocked the balloon from gathering intelligence and was able to study the balloon and its equipment.

A U.S. government official said that at least two U-2S reconnaissance aircraft were used to gather data on the balloon while it was over the Midwest, though it was not clear at which points in the balloon's flight it was tracked by U-2S aircraft. The War Zone commented that the U-2S's high flight ceiling, exceeding 70,000 feet (21,000 m), allowed it to observe the balloon from within relatively close proximity (including from above), and its electronic warfare suite allowed the aircraft to jam or monitor radio emissions from the balloon, including data transmissions directed upwards towards Chinese communications satellites.

Downing

Video of the balloon falling after its downing

External video
High-definition video of the shootdown

On February 4, the balloon drifted to the Carolinas. The Federal Aviation Administration closed airspace over the area in one of the largest temporary flight restrictions in U.S. history, "more than five times the restricted airspace surrounding Washington, D.C., and nearly double the area of the state of Massachusetts". A ground stop was ordered on the coast at Myrtle Beach International Airport and Charleston International Airport in South Carolina, and Wilmington International Airport in North Carolina. Military aircraft were reported to be over the Carolinas. U.S. officials later stated that this was in preparation for the eventual downing of the balloon within American territorial waters over the Atlantic.

The balloon was shot down off the coast of Surfside Beach, South Carolina, at an altitude of 58,000 feet (18,000 m) by an AIM-9X Sidewinder fired from a U.S. Air Force F-22 Raptor that had departed from Langley Air Force Base; the downing occurred at 2:39 p.m. eastern time. The downing was the first recorded by a F-22 and the first of an aircraft over U.S. territory since World War II.

Debris recovery

Sailors assigned to Explosive Ordnance Disposal Group 2 recover a portion of the balloon from the Atlantic

Debris from the balloon was dispersed over an area of 2.25 square kilometres (0.87 sq mi), where the ocean was about 47 feet (14 m) deep and collection efforts were initiated for further inspection. VanHerck said the United States Navy was conducting recovery operations while the U.S. Coast Guard was securing the region where the debris fell. Guided-missile destroyer USS Oscar Austin, guided-missile cruiser USS Philippine Sea, and dock landing ship USS Carter Hall were tasked with retrieving the balloon wreckage, alongside Coast Guard cutters and helicopters, U.S. Navy divers, and FBI counterintelligence agents. General VanHerck stated that unmanned underwater vehicles controlled from rigid inflatable boats used side-scan sonar to locate the sunken debris. The unmanned vehicles analyzed the wreckage to identify potential threats to recovery divers, such as explosives or batteries with hazardous materials. The sunken payload was estimated to weigh more than 2,000 pounds (910 kg).

FBI Special Agents assigned to the Evidence Response Team process material recovered from the balloon.

On February 6, some of the downed payload was sent to the FBI Laboratory in Quantico, Virginia, for forensic analysis by the Bureau's Operational Technology Division. Possible balloon debris was spotted later on the South Carolina coast, where police were asking residents to report other sightings. China said it wanted the wreckage returned, but the U.S. said it had no plans to do so.

By February 13, the U.S. had recovered a significant portion of the balloon's payload off the South Carolina coast. The payload measured 30 feet (9.1 m) and had all of the craft's tech gear and antennas. NORTHCOM said: "Recovery operations near South Carolina continue. Crews have been able to recover significant debris from the site, including all of the priority sensor and electronics pieces identified as well as large sections of the structure. Weather permitted crane operations at the site late last week. Due to weather today, underwater recovery activities are limited but will resume as conditions permit."

On February 17, the U.S. military said that recovery operations have concluded for the balloon after final debris were located and retrieved.

Response and reactions

United States

Federal government

Secretary of State Blinken postponed a scheduled diplomatic trip to China in response, which would have been the first such visit since 2018. The White House did not want to announce the balloon's incursion to protect Blinken's trip, but press and social media interest made Pentagon officials comment.

F-22 Raptor takes off from Joint Base Langley-Eustis during the balloon incident

In response to questions regarding the situation, on February 4, Biden said, "We're going to take care of it." Later that day, U.S. officials disclosed that three days earlier he had granted permission to down the balloon.

Pentagon officials stated that there was no earlier opportunity to shoot down over water, rebutting Trump and other Republicans who criticized the Biden administration for not shooting down the balloon earlier. Senate Democratic Leader Chuck Schumer added: "The bottom line here is that shooting down the balloon over water wasn't just the safest option, but it was the one that maximized our intel gain."

On February 6, U.S. Deputy Secretary of State Wendy Sherman briefed 150 diplomats from about 40 embassies on China's balloon surveillance program, said by U.S. officials to have been run for several years by the People's Liberation Army from Hainan on China's south coast, as part of an effort to "name and shame" Chinese espionage by publicly calling it out Officials are separately reaching out to countries where they say there have been at least two dozen such overflights since 2018, including Japan, India, Vietnam, Taiwan and the Philippines in addition to North and South America.

The U.S. House Armed Services Committee held a February 7 hearing on wide-ranging Chinese military and intelligence threats including the balloon incursions. Committee chair Republican Mike Rogers characterized the balloon as an intentionally calculated show of force. A U.S. official told The Washington Post there was no sense that the balloon was a deliberate provocation, as it was part of an ongoing global surveillance program. The U.S. House of Representatives voted 419–0 to adopt a resolution condemning China for the incident.

Trump called reports of intrusions during his administration "fake disinformation"; and his ex-top national security officials said they were unaware of any balloon incursions during their tenure. Biden administration National Security Advisor Jake Sullivan said that improved airspace surveillance ordered by Biden after he took office had detected the previous incursions and "enhanced our capacity to be able to detect things that the Trump administration was unable to detect".

On February 10, the U.S. added six entities accused of being associated with China's balloon surveillance program to the U.S. Commerce Department Bureau of Industry and Security's Entity List, a U.S. exports blacklist. They are: Beijing Nanjiang Aerospace Technology Co., Ltd.; China Electronics Technology Group Corporation 48th Research Institute; Dongguan Lingkong Remote Sensing Technology Co., Ltd.; Eagles Men Aviation Science and Technology Group Co., Ltd. (EMAST); Guangzhou Tian-Hai-Xiang Aviation Technology Co., Ltd.; and Shanxi Eagles Men Aviation Science and Technology Group Co., Ltd.

On February 14, intelligence officials began to explore the possibility that the balloon had not been intended to penetrate U.S. airspace and transit the continental United States but that Chinese authorities had instead sought to engage in more typical surveillance activities near Guam before the balloon potentially became blown off course. These discussions suggested that the international incident caused by the balloon's cross-continental transit may have been partly the result of an accident.

Canada

Canadian officials and Global Affairs Canada summoned the Chinese Ambassador to Canada, Cong Peiwu, to Ottawa while the Department of National Defence announced it was monitoring the situation alongside the United States through NORAD. A statement from the Canadian Armed Forces said there was no threat to Canadians, and Minister of Foreign Affairs Mélanie Joly would remain in contact with Blinken.

China

On February 3, spokesperson of the Chinese Ministry of Foreign Affairs Mao Ning said: "It is a civilian airship used for research, mainly meteorological, purposes. Affected by the Westerlies and with limited self-steering capability, the airship deviated far from its planned course." She said China regretted the unintentional incident, citing force majeure. On February 6, Mao said that the U.S. "hyped up the incident on purpose and even used force to attack", and called the shoot down "an unacceptable and irresponsible action".

Following the downing on February 5, Vice Foreign Minister Xie Feng said he had filed a formal complaint with the U.S. Embassy in response to the incident. Xie accused the United States of indiscriminately using force against the civilian airship that was about to leave U.S. airspace in violation of "the spirit of international law and international practice" and said that the Chinese government reserved the right to "take further necessary responses". On February 6, a Chinese diplomat said in an interview with French news network LCI that the United States should return the recovered balloon debris to China.

The incident coincided in timing with the release of science fiction film The Wandering Earth 2 in mainland China, causing some netizens and media to jokingly refer to the incident as "The Wandering Balloon".

On February 12, Chinese authorities said that they had discovered an unidentified flying object near the Yellow Sea off eastern Shandong, and were preparing to shoot it down.

On February 13, Chinese Foreign Affairs spokesperson Wang Wenbin said that the U.S. high-altitude balloons had "illegally crossed China's airspace" more than ten times since 2022 and also accused the U.S. of carrying out reconnaissance against China and wiretapping against targets around the world. The U.S. denied China's surveillance balloons claim and, according to CNN, Wang's accusation was made without evidence.

NATO

NATO secretary-general Jens Stoltenberg said the balloon "confirms a pattern of Chinese behavior where we see that China has invested heavily in new capabilities, including different types of surveillance and intelligence platforms", and that it presents security challenges for the members of the alliance.

Other countries

Amidst the ongoing Australia–China trade war, Australian Minister for Foreign Affairs Penny Wong said: "I believe the US has managed this as carefully as possible. They brought the balloon down over their own territorial waters."

Venezuela's foreign ministry condemned the United States for shooting down what they stated was an unmanned civilian aircraft which posed no threat.

Prime Minister Rishi Sunak stated on February 13 that the United Kingdom's government would do "whatever it takes" to defend the country from observation balloons. He added that the Royal Air Force had placed Typhoon jets on stand-by. Furthermore, ex-MI6 chief Sir Alex Younger, said that due to the systematic nature of China's surveillance program, the UK must "wake up" to China's threat to global security.

Media reactions

Analysis

Michael Clarke, a British defense analyst, said that China wanted to be 'noticed' with the balloon. He suggested that the spy balloon fly-over was a response to an agreement signed by the United States and the Philippines on February 2, 2023, which allowed the US military access to four more military bases in the Philippines as part of a joint pushback against what Clarke called China's illegal nine dash line claims to the South China Sea.

John Blaxland, a professor of international security and intelligence studies at the Australian National University, said that the Chinese likely expected the balloon to be detected, and he further suggested that the balloon being detected was the goal. Blaxland believes that one of the reasons the balloon was launched, was to embarrass the US, with intelligence gathering being a secondary objective. He also said that the balloon could be designed to test the resolve of Washington as well as gather information about American detection capabilities and reaction.

On the shooting of the balloon, Christopher Twomey, a security scholar, said that any Chinese response would be restrained and that China would want to "sweep this under the rug" and emphasize senior-level visits within months. The Washington Post columnist Ishaan Tharoor contextualized the incident as part of Cold War II.

Gregory Falco, an aerospace security expert at the Johns Hopkins University, commented on the surveillance balloon's technology. He said that the balloon was part of "China's hybrid communications architecture" that relays surveillance data to satellites in Low Earth Orbit and back to Chinese ground stations. He also said that the large solar panels, antenna and the navigation capabilities of the balloon indicated it was indeed engaged for surveillance and not weather data collection.

Satire

The incident was satirized in the cold open of the show Saturday Night Live the evening after it was shot down. In the sketch, performer Bowen Yang portrayed an anthropomorphized depiction of the downed balloon being interviewed by MSNBC journalist Katy Tur (played by Chloe Fineman). Some sources paid particular attention to Yang's line, "Congrats! You shot a balloon!", with USA Today using it in the headline of its coverage. YouTube duo Josh Pieters and Archie Manners would launch a weather balloon with a camera towards the Chinese Embassy in London to spy on China since embassies are legally part of the guest country.

Further incursions and responses

Further information: List of high-altitude object events in 2023

On February 3, the U.S. Department of Defense stated that a second Chinese surveillance balloon had been detected, this one flying over Latin America. The Costa Rican General Directorate of Civil Aviation confirmed the incursion by an object "not of Costa Rican origin" that locals had first seen on February 2. The Colombian Air Force said that on the morning of February 3, it had detected an object with "characteristics similar to those of a balloon" at a height of 55,000 feet (17,000 m) and traveling at a speed of 25 knots (46 kilometres per hour; 29 miles per hour), and after determining it was not a threat to national security and defense or to air safety, had continued to track it until it left Colombian airspace. Sightings of the balloon were also reported from Venezuela, specifically from Maracaibo. On February 6, Mao Ning, the spokeswoman for the Chinese government, confirmed the balloon belongs to China, but said that it was used for "flight tests" and was blown off-course in much the same manner as the one spotted over North America.

On February 10, another high-altitude object was shot down on the vicinity of Deadhorse, Alaska, over the Beaufort Sea; recovery efforts by the Alaska National Guard on the sea ice are on-going.

On February 11, on previous orders of Canadian Prime Minister Justin Trudeau, a "small, cylindrical object" was shot down over the Yukon Territory for violating Canadian air space; both U.S. and Canadian aircraft had scrambled, and a U.S. F-22 jet fighter made the kill.

On February 12, the US military shot down a fourth unidentified object over Lake Huron, within the maritime territory of Michigan.

On February 14, the US government announced that the latter three high-altitude objects shot down over the North America were likely private entities with no relations to China. Further analysis and debris collections were underway.

See also

• 1960 U-2 incident
• 2023 Alaska high-altitude object
• 2023 Lake Huron high-altitude object
• 2023 Yukon high-altitude object
• Balloon buster
• Fu-Go balloon bomb
• Hainan Island incident
• List of high-altitude object events in 2023
• Project Genetrix